Argon is used widely in steel manufacturing, cutting and welding of metals, metal sintering, electronic component fabrication, and other processes that require the a non-reactive gas for blanketing, purging, and heat transfer purposes. After use in these applications, the argon may contain contaminants such as hydrocarbons, carbon oxides, hydrogen, nitrogen, oxygen, water, and particulate material. Because argon is a relatively expensive gas, it is economically desirable in many cases to purify the contaminated argon and recycle the purified gas to the argon-using process.
Argon can be purified for recycle by combinations of gas processing steps including filtration, condensation, cryogenic distillation, pressure swing adsorption or pressure vacuum swing adsorption, temperature swing adsorption, catalytic oxidation, and gettering. The specific combination of processing steps will depend on the contaminants present in the crude argon to be purified, the concentration of the contaminants, and the required purity of the recycled gas. It is desirable to minimize the complexity of the argon purification system and utilize only those steps required to meet recycled gas purity requirements at acceptable cost.
There is a need in the art for improved argon recovery processes that provide high purity argon for recycle using compact and efficient equipment capable of high argon recovery at low cost. This need is addressed by the embodiments of the present invention described below and defined by the claims that follow.